无刷新预览所选择的图片示例代码_javascript技巧

代码如下

复制代码 代码如下:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript">
//本地图片预览
function setImagePreview(fieldupload, image, imagediv) {
var docObj = document.getElementById(fieldupload);
var imgObjPreview = document.getElementById(image);
if (docObj.files && docObj.files[0]) {
//火狐下，直接设img属性
imgObjPreview.style.display = 'block';
imgObjPreview.style.width = '150px';
imgObjPreview.style.height = '150px';
//imgObjPreview.src = docObj.files[0].getAsDataURL();
//火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式
imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);
} else {
//IE下，使用滤镜
docObj.select();
var imgSrc = document.selection.createRange().text;
var localImagId = document.getElementById(imagediv);
//必须设置初始大小
localImagId.style.width = "150px";
localImagId.style.height = "150px";
//图片异常的捕捉，防止用户修改后缀来伪造图片
try {
localImagId.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)"; localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;
} catch (e) {
alert("您上传的图片格式不正确，请重新选择!");
return false;
}
imgObjPreview.style.display = 'none';
document.selection.empty();
}
return true;
}
</script>
</head>

<body>
<div id="localImag"> <img id="preview" width="150px" height="150px" src="http://images.cnblogs.com/cnblogs_com/yc-755909659/559257/o_%e6%9a%82%e6%97%a0%e5%9b%be%e7%89%87.gif" alt="" /></div>
<div>
<input type="file" onchange="javascript:setImagePreview('upload','preview','localImag');" id="upload" />
</div>
</body>
</html>